Why has the generation not changed after adding optimisers?

Adding optimisers in the inverter task will not automatically change the generation. The generation is a product of the kWp of the inverter, the kk value (which is based on the pitch, orientation and location of the panels) and the shading factor.

If panels remain grouped the same, their shading factors and kk value will not change. With optimisers, you can put panels in separate shading groups. This allows Easy PV to factor in differences in the kk value and shading factor for the panels in each group on a single string. Without shading groups the generation will not change because the kk value and shading factor will be the same on the whole string, as it would be without optimsers.